Embodiments relate to a transmitter, a receiver, a system having the same and a method of communication between a transmitter and a receiver.
In a network, a transmitter Tx, operating according to a transmitter clock (TCLK), sends information over a communication channel to a receiver Rx, operating according to a receiver clock (RCLK). Each clock in the network is not ideal, in that the frequency of TCLK and RCLK may be different leading to drifts in the clock signal over time and/or the clock signal exhibiting jitters.
As illustrated in FIG. 1, due to these drifts and jitters, a time at the transmitter clock TCLK, illustrated on the x-axis, and a time at the receiver clock RCLK, illustrated on the y-axis, may become unsynchronized. In a network with ideal clocks, the receiver clock RCLK, shown on the y-axis, would increase at the same rate as the time at the transmitter clock TCLK, shown on the x-axis, making the line shown in FIG. 1 increase at a 45 degree slope. Further, in a network with ideal clocks, the line shown would not exhibit random jitters. To communicate with each other, the transmitter Tx and the receiver Rx need to account for the fact that the clocks at each end may not be synchronized.
Conventionally, clock errors are corrected in “tight synchronization” schemes by occasionally resynchronizing the transmitter Tx and the receiver Rx. Tight synchronization can be achieved by either separating data transmission between the transmitter Tx and the receiver Rx from synchronization or by incorporating synchronization with data transmission. In a conventional tight synchronization scheme that handles data transmission separately from synchronization, synchronization is achieved by periodic transmission of pilot signals. In a conventional tight synchronization scheme that combines synchronization with data transmission, data bits are modulated differentially at the transmitter Tx to enable synchronization at the receiver Rx.